Electrical coulomb-meter.



No. 680,233. Patented Aug. I3, I90 S. E. DUANE.

ELECTRICAL GOULOMB METER.

(Application fllediDee. 10, 1900.) (No Model.)

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UNITED STATES PATENT OFFICE. I

SAMUEL E. DOANE, OF MARLBORO, MASSACHUSETTS.

ELECTRICAL CO ULOMB-METER.

SPECIFICATION formingpart of Letters Patent No, 680,233, dated August 13, 1901.

Application filed December 10, 1900. Serial No. 39,251. (No model.)

To all whom, it may concern-.-

Be it known that I, SAMUEL E. DOANE, a citizen of the United States, residing at Marlboro, county of Middlesex, and State of Massachusetts, have made a new and useful Invention in Electrical Coulomb-Meters, of which the following is a specification. 7 My invention has for its object to construct and provide a coulomb-meter of a duplex nature upon the principle of the well-known voltameter, in which the currents in two circuits may be compared by or through the agency of the gases liberated by them. I have in mind particularly to provide means whereby the relative amounts of current used by two electric incandescent lamps when connected in multiple may be quickly and correctly indicated.

My invention will be understood by referring to the accompanying drawings, in which- Figure 1 is a side elevational view of the complete apparatus, a part thereof being broken away to better illustrate the interior structure, the numbers on the lower part of the scale and the filling-tube and its cork being shown in dotted lines, two incandescent electric lamps being shown in circuit therewith for the purpose of illustrating its especial application or use; and Fig. 2 is a detail and diagrammatic view of the electrical circuit connections of the instrument.

Referring now to the drawings in detail for a full and clear understanding of the invention, such as will enable others skilled in the art to construct and use the same, A represents a glass jar or vessel of the desired capacity, and R a rubber or other insulating stopper therefor, 0 being a screw-threaded metallic cap or cover adapted to secure the parts together through the agency ofscrewthreads near the mouth of the jar or vessel.

D and D are angular metallic arms soldered or otherwise secured to the opposite sides of the cap or cover 0 and each sustaining any well-known form of socket for connecting theretoan electric lamp L L or any other electrical translating device the current-utilizing capacity of which it is desired to test.

T and T are glass or equivalent transparent tubes of the desired lengths secured side by side in openings in the stopper B, said such manner as to be gas-tight.

tubes extending downward a definite distance, as shown by dotted lines, into the vessel A and sealed or closed at their upper ends in E is a metallic clip for .firmly securing them together at their tops.

S is a scale calibrated from zero to any required number of marks and in accordance with the use to which the instrument is to be put, said scale being secured between the two tubes T and T by the clip E and in such manner as to be common to both tubes and to give a correct comparative reading of the height of the liquid therein when forceddown- I ward by the decomposed gases.

G is a short vent-tube, open at both ends, extending through the stopper B. into the ves sel and provided with a small stopper F.

Referring now to Fig. 2 of the drawings for a clear understanding of the electrical circuit connections, 10 10 represent conductors running to the source of electrical energy, B and B being binding-posts, the former secured directly to the metallic cap or cover 0 and the latter secured to, but insulatedtherefrom. s is a metallic strip connecting the binding-post B to the two conductors 10, each of which is connected with one of a pair of thin flat electrodes 6 e, seated in and passing through the walls of the tubes T T, a corresponding pair of like flat electrodes 6 e, located parallel with and in close proximity to the others, being similarly sustained by the tubes and connected by conductors w? 10 with the insulated contacts of the socket for the electric lamps L L, these sockets being connected, as is apparent on inspection of Fig. 1, directly to the screw-threaded caps of the lamps L L through the arms D D, to which the binding-post B is electrically connected.

It is operated as follows: In order to test the current utilized by two electrical translating devices (here shown as incandescent lampsL L) the vessel A is first partially filled with a weak solution of sulfuric acid (ten per cent.) or other suitable liquid. It is then turned upside down until the tubes are filled with liquid, after which it is restored to its normal position and the cork in the vent-tube removed. The lamps L L to be tested are now secured in their sockets and the current out at the lower ends of the tubes.

turned on through the conductors w. When the lamps have been thus connected up in circuit, the action of the current liberates gas between the electrodes 6 e, which gas rises in the tubes T T in direct quantitative proportion to the amount of current passed, respectively, by each lamp, and at the same time tends to force the liquid downward and The current is allowed to pass for a periodsay until the liquid in the tube T registers 100. The liquid in the tube T will then indicate by the amount it has fallen the coulombs the lamp L has utilized in terms of the coulombs utilized by the lamp L.

I am aware that heretofore an electrodynamic indicating instrument of a duplex naturehas been devised. for the purpose of enabling one to obtain simultaneous readings upon an index-scale common to two independent moving electrodynamic systems provided each with an index needle or hand pointing toward the common scale or index, and I make no claim hereinafter broad enough to include such a structure, my most generic claim being directed to an instrument based upon the principle of the wellknown voltaineter and which by reason of its simplicity of structure renders it ready for use at all times without possibility of any charge in calibration.

Although my invention is especially designed for making comparative tests as to the current used by incandescent electric lamps, I do not thus specifically limit its use, as it is obvious that it may be used in many places in the electrical art and that the common or intermediate scale S may be calibrated to meet any duplex or double use to which it may be put.

It is of course obvious that where such an instrument is to be used for making a comparative test of independent electrical generators the electrodes e e in each tube should betconnected to independent pairs of bindingposts, such matters being well within the skill of those versed in the art.

I am aware that an electric-current meter has heretofore been devised with one electrode of a circuit in each leg of a U-shaped tube, the upper ends of which are provided with valves for permitting the escape therefrom of the gases liberated, an index or scale being provided between the tubes for indicating the amount of liquid decomposed,

and I make no claim hereinafter broad enough to include such a structure, my invention being directed to a coulomb-meter, as hereinbefore described, in which the relative volumes of the liberated gases are retained in the upper or sealed ends of the tubes, such an instrument giving larger comparative indications of the relative differences of current than would be possible with a coulomb-meterwhere the upper ends of the tubes are so arranged as to permit the liberated gas to escape.

Having thus described my invention, what I claim, and desire to secure by Letters Patent of the United States, is

'1. A coulomb-meter provided with means for giving simultaneous comparative indications of the volumes of the liberated gases, substantially as described.

2. A coulomb-meter, consisting of means for sim ultaneously electrolyticallyliberating, storing and indicating independent volumes of gases, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

SAMUEL DOANE.

Witnesses:

GEORGE A. VVHITING, WILLIAM H. ROBERTS. 

